Category Archive: .Sagan, Carl

Science is a way of thinking much more than it is a body of knowledge. Its goal is to find out how the world works, to seek what regularities there may be, to penetrate the connections of things—from subnuclear particles, which may be the constituents of all matter, to living organisms, the human social community, and thence to the cosmos as a whole. Our intuition is by no means an infallible guide. Our perceptions may be distorted by training and prejudice or merely because of the limitations of our sense organs, which, of course, perceive directly but a small fraction of the phenomena of the world. Even so straightforward a question as whether in the absence of friction a pound of lead falls faster than a gram of fluff was answered incorrectly by Aristotle and almost everyone else before the time of Galileo. Science is based on experiment, on a willingness to challenge old dogma, on an openness to see the universe as it really is. Accordingly, science sometimes requires courage—at the very least the courage to question the conventional wisdom.

Beyond this the main trick of science is to really think of something: the shape of clouds and their occasional sharp bottom edges at the same altitude everywhere in the sky; the formation of the dewdrop on a leaf; the origin of a name or a word—Shakespeare, say, or “philanthropic”; the reason for human social customs—the incest taboo, for example; how it is that a lens in sunlight can make paper burn; how a “walking stick” got to look so much like a twig; why the Moon seems to follow us as we walk; what prevents us from digging a hole down to the center of the Earth; what the definition is of “down” on a spherical Earth; how it is possible for the body to convert yesterday’s lunch into today’s muscle and sinew; or how far is up—does the universe go on forever, or if it does not, is there any meaning to the question of what lies on the other side? Some of these questions are pretty easy. Others, especially the last, are mys­teries to which no one even today knows the answer. They are natural questions to ask. Every culture has posed such questions in one way or another. Almost always the proposed answers are in the nature of “Just So Stories,” attempted explanations divorced from experiment, or even from careful comparative observations.

But the scientific cast of mind examines the world critically as if many alternative worlds might exist, as if other things might be here which are not. Then we are forced to ask why what we see is present and not something else. Why are the Sun and the Moon and the planets spheres? Why not pyramids, or cubes, or dodecahedra? Why not irregular, jumbly shapes? Why so symmetrical worlds? If you spend any time spinning hypotheses, checking to see whether they make sense, whether they conform to what else we know, thinking of tests you can pose to substantiate or deflate your hypotheses, you will find yourself doing science. And as you come to practice this habit of thought more and more you will get better and better at it. To penetrate into the heart of the thing—even a little thing, a blade of grass, as Walt Whitman said—is to experience a kind of exhilaration that, it may be, only human beings of all the beings on this planet can feel. We are an intelligent species and the use of our intelligence quite properly gives us pleasure. In this respect the brain is like a muscle. When we think well, we feel good. Understanding is a kind of ecstasy. [15]

The methods of science — with all its imperfections — can be used to improve social, political, and economic systems, and this is, I think, true no matter what criterion of improvement is adopted. How is this possible if science is based on experiment? Humans are not electrons or laboratory rats. But every act of Congress, every Supreme Court decision, every Presidential National Security Directive, every change in the Prime Rate is an experiment. Every shift in eco­nomic policy, every increase or decrease in funding of Head Start, every toughening of criminal sentences is an experiment. Exchanging needles, making condoms available, or decriminalizing marijuana are all experiments. Doing nothing to help Abyssinia against Italy, or to prevent Nazi Germany from invading the Rhineland, was an experiment. Communism in Eastern Europe, the Soviet Union, and China was an experiment. Privatizing mental health care or prisons is an experiment. Japan and West Germany investing a great deal in science and technology and next to nothing on defense — and finding that their economies boomed — was an experiment. Handguns are available for self-protection in Seattle, but not in nearby Vancouver, Canada; handgun killings are five times more common and the handgun suicide rate is ten times greater in Seattle. Guns make impulsive killing easy. This is also an experiment. In almost all of these cases, adequate control experiments are not performed, or variables are insufficiently separated. Nevertheless, to a certain and often useful degree, policy ideas can be tested. The great waste would be to ignore the results of social experiments because they seem to be ideologically unpalatable. [423]

About two-thirds of the mass of the human brain is in the cerebral cortex, devoted to intuition and reason. Humans have evolved gregariously. We delight in each other’s company; we care for one another. We cooperate. Altruism is built into us. We have brilliantly deciphered some of the patterns of Nature. We have sufficient motivation to work together and the ability to figure out how to do it. If we are willing to contemplate nuclear war and the wholesale destruction of our emerging global society, should we not also be willing to contemplate a wholesale restructuring of our societies? From an extraterrestrial perspective, our global civilization is clearly on the edge of failure in the most important task it faces: to preserve the lives and well-being of the citizens of the planet. Should we not then be willing lo explore vigorously, in every nation, major changes in the traditional ways of doing things, a fundamental redesign of economic, political, social and religious institutions? [272]

If we teach only the findings and products of science—no matter how useful and even inspiring they may be—without communicating its critical method, how can the average person possibly distinguish science from pseudoscience? Both then are presented as unsupported assertion.

Why instead did the West slumber through a thousand years of darkness until Columbus and Copernicus and their contemporaries rediscovered the work done in Alexandria? I cannot give you a simple answer. But I do know this: there is no record, in the entire history of the Library, that any of its illustrious scientists and scholars ever seriously chal­lenged the political, economic and religious assumptions of their society. The permanence of the stars was questioned; the justice of slavery was not. Science and learning in general were the preserve of a privileged few. The vast popula­tion of the city had not the vaguest notion of the great discoveries taking place within the Library. New findings were not explained or popularized. The research benefited them little. Discoveries in mechanics and steam technology were applied mainly to the perfection of weapons, the encouragement of superstition, the amusement of kings. The scientists never grasped the potential of machines to free people. The great intellectual achievements of antiquity had few imme­diate practical applications. Science never captured the imagination of the multitude. There was no counterbalance to stagnation, to pessimism, to the most abject surrenders to mysticism. When, at long last, the mob came to burn the Library down, there was nobody to stop them. [278]

There is no other species on Earth that does science. It is, so far, entirely a human invention, evolved by natural selection in the cerebral cortex for one simple reason: it works. It is not perfect. It can be misused. It is only a tool. But it is by far the best tool we have, self-correcting, ongoing, applicable to everything. It has two rules. First: there are no sacred truths; all assumptions must be critically examined; arguments from authority are worthless. Second: whatever is inconsistent with the facts must be discarded or revised. We must understand the Cosmos as it is and not confuse how it is with how we wish it to be. The obvious is sometimes false; the unexpected is sometimes true. Humans everywhere share the same goals when the context is large enough. And the study of the Cosmos provides the largest possible context. [276]

Now, what’s the difference between an invisible, incorporeal, floating dragon who spits heatless fire and no dragon at all? If there’s no way to disprove my contention, no conceivable experiment that would count against it, what does it mean to say that my dragon exists? Your inability to invalidate my hypothesis is not at all the same thing as proving it true. Claims that cannot be tested, assertions immune to disproof are veridically worthless, whatever value they may have in inspiring us or in exciting our sense of wonder. What I’m asking you to do comes down to believing, in the absence of evidence, on my say-so. [171]

I think the first thing, in a democracy, where there is at least some pretense about the people controlling government policy, is that every democratic process ought to be used. You can make sure that those whom you vote for have rational views on these matters. You can work hard to make sure that there is a real difference of opinion in the alternative candidates. You can write letters to newspapers and so on. But more important than any of that, I believe, is that each of us must equip him- or herself with a “baloney-detection kit.” [257]